Why Did Elon Musk Spend $218 Million (in stock) on an Ultracapacitor Company? The Answer may be in ‘Dry Electrode Technology’

          Does Tesla want ultracapacitors? Or dry electrode technology?

Earlier this month, Tesla announced plans to acquire Maxwell Technologies, an established, 380-employee ultracapacitor and storage materials firm for $218 million in an all-stock deal. It’s easy for a transaction of this sort to get lost in the Tesla media cycle.

 

Elon Musk was once intent on studying ultracapacitors at Stanford University, long before Tesla was even a gleam in his eye. Apparently, Musk is still charged up on the technology.

Maxwell’s total revenue was $91.6 million in the first nine months of 2018, with losses of $30.2 million. Revenue in 2017 was $130.3 million with losses of $43.1 million.

So why is Tesla paying above book value (but still not enough, according to some investors) for a money-losing firm (here’s Maxwell’s SEC filing)?

Does Tesla want ultracapacitors?

Maxwell’s core business is ultracapacitors, the wide-temperature-range, high-power-density energy storage component that can rapidly charge and discharge. Also known as supercaps or electronic double layer capacitors, ultracapacitors are geared for high-power and high-cycle applications.

Batteries use a chemical process to store energy, while ultracapacitors store a static electric charge — physically separating positive and negative charges.

Maxwell’s ultracaps deliver peak power as well as regenerative braking, voltage stabilization, backup power and hybrid stop/start. Ultracaps are also used to power the pitch control adjustment in wind turbines during sudden wind speed changes, since replacing batteries at 500 feet above the ground is tricky.

In a previous interview, Maxwell’s CEO estimated that there is $5,000 worth of ultracaps in the typical wind turbine and $15,000 per electric bus. Maxwell declined to respond to GTM to update those figures.

Or dry electrode technology?

But Maxwell’s allure might not be its ultracapacitors — it might be the dry electrode technology developed by Maxwell that really intrigues Elon Musk.

The “dry” in “dry electrode technology” refers to an ultracapacitor manufacturing process that Maxwell claims can improve battery costs, performance and lifetime across a variety of lithium-ion battery chemistries. 

Maxwell states, in a release, that its dry electrode manufacturing technology, historically used to make ultracapacitors, is “a breakthrough technology that can be applied to the manufacturing of batteries.”

A white paper from Maxwell claims that its dry battery electrode (DBE) coating technology can be used with “classical and advanced” lithium-ion battery chemistries, but “unlike conventional slurry cast wet coated electrode, Maxwell’s DBE produces a thick electrode that allows for high energy density cells with better discharge rate capability than those of a wet coated electrode.” (Right: Passive dry electrode schematic)

A presentation from the company claims it has “demonstrated” an energy density of greater than 300 watt-hours per kilogram and has “identified” a path to greater than 500 watt-hours per kilogram. Maxwell claims to have used the process with a number of available anode materials.

A battery expert colleague notes that solvent-free electrode manufacturing “might be worth $200 million” if Maxwell “has really eliminated the toxic solvent without compromising on performance.” Maxwell’s patent filings indicate that work is being done to eliminate solvent usage in both dry-processing and melt-processing of binders.

Other ultracap suppliers include Tokin, Seiko, Eaton, CAP-XX, LS Ultracapacitor, Ioxus and Skeleton.

This deal was Tesla’s fifth acquisition since its founding; the others being manufacturing-automation firm Perbix, SolarCity, Riviera Tool and Grohmann Engineering.

During Maxwell’s third-quarter 2018 conference call, CEO Franz Fink noted that its dry electrode business was looking for a partner to provide “significant financial support” and expertise in EVs or energy storage systems. 

If this deal goes through in the coming quarters, Maxwell’s CEO will have gotten his wish.

Story from GTM (GreenTechMedia) – Eric Wescoff

Rivian patent reveals R1T auxiliary battery that pushes range beyond 400 miles

Rivian CEO RJ Scaringe previously mentioned that his electric truck company is developing an auxiliary battery that acts as a “digital jerry can” for its vehicles, allowing them to travel beyond their listed range. Thanks to a recently published patent application, more details on this auxiliary battery system are now available. 

The patent, titled “Electric Vehicle With Modular Removable Auxiliary Battery With Integrated Cooling,” describes an external battery module that can be fitted to an electric vehicle, thereby providing it with additional range.

This is especially important for Rivian’s trucks, since they are designed to go off-road. Thus, the company notes that there is a need for an “auxiliary battery system for an electric automotive vehicle to increase the range of the electric vehicle, and in particular, an auxiliary battery system that can be carried by the electric vehicle.”

 As could be seen in the patent application, the auxiliary battery systemwould be installed on the cargo area of a truck. In the case of the R1T pickup, for example, the battery module would be fitted on the truck’s bed. The entire module also includes latching mechanisms and connectors, which are designed for easy installation and removal. 

Illustrations depicting Rivian’s auxiliary battery system. (Photo: Rivian Automotive)

Perhaps more impressively, Rivian’s design for its auxiliary battery utilizes the cooling systems of the vehicle itself. Upon installation of the battery unit, Rivian notes that the vehicle’s systems would perform necessary adjustments, ensuring that ride quality and driveability do not get compromised or unnecessarily changed. Rivian outlines this process in the following section:

“When outfitted with the auxiliary battery, the electric vehicle can detect the fact that the auxiliary battery is attached to (e.g., mounted in) the electric vehicle (e.g., in cargo bed) and automatically set one of multiple predetermined feature sets, e.g., that pertain to driving performance of the electric vehicle.

Such feature sets may set, for example, certain suspension characteristics appropriate for the attachment of the auxiliary battery, such as, e.g., a setting for firmness of ride of the vehicle, braking performance/sensitivity, nominal suspension height, effective steering ratio, etc.” 

It should be noted that the auxiliary battery module design outlined in Rivian’s recently-published patent appears to be optimized for the R1T pickup truck.

Based on the illustrations provided by the company, the external battery seems to take up a substantial amount of space in the all-electric pickup’s bed. With this in mind, it remains to be seen how the company would design a similar battery solution for the R1S SUV, which does not have a bed like the R1T.

Nevertheless, considering Rivian’s polished approach to its designs, it is quite exciting to see how the company would equip a seven-seater SUV with a range-extending battery module.

Illustrations depicting Rivian’s auxiliary battery system. (Photo: Rivian Automotive)

RJ Scaringe noted in a previous interview that one of the reasons behind Rivian’s extra large battery packs (offered at 105 kWh, 135 kWh, and 180 kWh configurations) is to ensure that drivers would have enough range for their adventure needs.

This certainly appears to be the theme with Rivian’s vehicles, as could be seen in its top-tier variants’ range of 400 miles per charge. Coupled with an auxiliary battery system, the company’s trucks could very well close in or even exceed the 500-miles per charge mark. 

Similar to other new automakers such as Tesla, Rivian’s first vehicles are made for the luxury niche, not the mass market.

As noted by RJ Scaringe in an interview with Green Tech Media, Rivian’s target demographic are the people who are “spending $70,000 or $80,000 on a GMC Denali or a Chevy Suburban or a Land Rover Discovery or a fully loaded Ford F150.” For these potential customers, the company can tolerate no compromises, and in Scaringe’s words, “under-promise and over-deliver.” This is especially true with regards to the R1T and the R1S’ range. 

Rivian’s patent application for its auxiliary battery system could be accessed here.

Researchers at Melbourne’s RMIT University Convert CO2 back into Coal in Carbon Breakthrough – (Captured) Carbon produced could also be used as an electrode … Watch Video

 

 

Australian scientists have unlocked a new and more “efficient” way  to turn carbon dioxide back into solid coal, in a world-first breakthrough that could combat rising greenhouse gas levels.

Researchers at Melbourne’s RMIT University have used liquid metals to convert CO2 from a gas to a solid at room temperature.

The technique has potential to “safely and permanently” remove CO2 from the atmosphere, according to the new study published in the journal Nature Communications.

Carbon technologies have previously tended to focus on compressing CO2 into a liquid form, transporting it to a suitable site and injecting it underground.

The use of underground injections to capture and store carbon is not economically viable and sparks fears of an environmental catastrophe due to possible leaks from the storage site.

However, the new technique transforms CO2 into solid flakes of carbon, similar to coal, which can be stored more easily and securely.

Carbon dioxide is dissolved into a beaker containing an electrolyte liquid, then a small amount of the liquid metal catalyst is added, which is then charged with an electrical current.

The electrical current serves as a catalyst to slowly converts the CO2 into solid flakes of carbon.

Watch how researchers made their discovery

This is a “crucial first step” to developing a more sustainable approach to converting CO2 into a solid, RMIT researcher Dr Torben Daeneke said, noting that more research is required cement the process.

He described the process as “efficient and scalable”.

“While we can’t literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock.

“To date, CO2 has only been converted into a solid at extremely high temperatures, making it industrially un-viable,” Dr Daeneke said.

The study’s lead author, Dr Dorna Esrafilzadeh, said the carbon produced could also be used as an electrode.

“A side benefit of the process is that the carbon can hold electrical charge, becoming a supercapacitor, so it could potentially be used as a component in future vehicles,” she said.

“The process also produces synthetic fuel as a by-product, which could also have industrial applications.”

The study was completed in collaboration with researchers from Germany (University of Munster), China (Nanjing University of Aeronautics and Astronautics), the US (North Carolina State University) and Australia (UNSW, University of Wollongong, Monash University, QUT).

Learn More About ‘Great Things from Small Things’ ~ Watch A Video on Our Current Project: Nano Enabled Batteries and Super Capacitors

Using Nanotechnology to Clean Water: A Conversation with Pedro Alvarez of Rice University (NEWT – Nano Enabled Water Treatment)

In this special anniversary episode of Stories from the NNI, Dr. Lisa Friedersdorf, Director of NNCO, talks to Prof. Pedro Alvarez, of Rice University. Pedro and Lisa discuss the role nanotechnology plays in water security, exciting research results and applications, and his thoughts on the NNI.

 

 

Read More: How Can Graphene Be Used in Desalination?

A NEW Battery Patent Application by Tesla could deliver Faster Charging, Longer Life and Lower Cost

Tesla’s battery research group, led by renowned battery boffin Jeff Dahn, has applied for a patent on a new battery cell chemistry that the company says could deliver faster charging, longer life and lower cost.
In the application, entitled “Novel battery systems based on two-additive electrolyte systems,” Dahn and his team explain that adding up to five different compounds to an electrolyte can improve battery performance, but they have devised a solution using only two additives, which reduces costs compared to other systems that rely on more additives. Above: Tesla’s Model S (Instagram: brian__self)

Above: A look at why (and how) battery advances could be a game changer for Tesla (Source: Wall Street Journal)

The new two-additive mixtures can be used with lithium nickel manganese cobalt (NMC) battery chemistries. NMC chemistry is used in several EV models, but Tesla uses an NCA chemistry for its vehicle battery cells. However, Tesla does use NMC in its stationary storage batteries. According to the patent application, the new technology would be useful for both EV and grid storage applications.

Above: Jeff Dahn seated in the driver’s seat of a Tesla Model S (Source: Dalhousie University News)

Electrek has published both a copy of the complete patent application and a detailed technical summary. This news coupled with Tesla’s recent acquisition of Maxwell Technologies could point to forthcoming advances in battery tech for the Silicon Valley automaker.

Written by Charles Morris; this article originally appeared in Charged. Source: Electrek Video – Wall Street Journal

Tesla’s incredible efficiency lead is becoming clear with range test against Audi e-tron and Jaguar I-Pace

With new premium electric SUVs hitting the market, Tesla is seeing some competition, but that competition is also highlighting Tesla’s incredible lead when it comes to efficiency.

Now a third-party range test against Audi e-tron and Jaguar I-Pace is confirming that the rest of the industry is behind when it comes to efficiency.

The range and efficiency test

German electric car rental company nextmove conducted the test between the three premium electric SUVs.

The company used a pre-series Audi e-tron since they haven’t started deliveries officially, a Tesla Model X 90D with a 90 kWh battery pack. and a Jaguar I-Pace, which is also equipped with a 90 kWh pack.

The test was performed with all three vehicles driving in parallel on a 87 km stretch of the Autobahn between the Munich airport and Landshut in Germany at an average speed of 120 km/h (75 mph):

The results for the Tesla Model X, Audi e-tron, and Jaguar I-Pace

According to nextmove’s test, the Model X came out on top with an impressive lead over the two competitors:

“In direct comparison, the Tesla Model X (drag coefficient: 0.25) performed best. The consumption was 24.8 kWh per 100 km ((39.9 kWh/100mi). The Audi e-tron (drag coefficient: 0.27) showed a 23% higher consumption of 30.5 kWh/100 km (49.1 kWh/100mi). The Jaguar I-Pace (drag coefficient: 0.29) had the highest consumption of 31.3 kWh/100 km (50,37 kWh/100mi). and required 26% more than the Model X. The significantly higher consumption of the I-Pace compared to the Model X confirms previous nextmove tests on the motorway.”

The numbers clearly show that Tesla needs a lot less energy to power its SUV:

They used a Model X 90D to have a more comparable battery size with the I-Pace and e-tron, but the vehicle is no longer available for sale.

For context, nextmove also used the Model X 100D in the range comparison for what is available today:

Electrek’s Take

We already noted the disappointing efficiency in our reviews of the Audi e-tronand Jaguar I-Pace, but it’s interesting to have a direct comparison on the same road at the same time.

Also, it’s especially impressive when we consider that the Model X is bigger than both of those vehicles and therefore, it shouldn’t be more efficient.

We even noted in our review of the I-Pace that we wouldn’t even compare it to the Model X because it is more of a sedan than a SUV.

As for Audi, I think that they are intentionally giving up their efficiency in order to protect the battery pack and get a higher charge rate.

They clearly have a large buffer for their battery pack, which has a capacity of 95 kWh, but I don’t think you get access to more than 85 kWh out of it.

That’s how they manage to achieve an impressive charge rate of over 150 kWand maintain it for so long since the battery is not actually as full as you’d think and it also enables a lower average state-of-charge, which could be good for the longevity of the pack.

The disadvantage of it is that you are carrying around 15% more battery than you are ever going to use and that’s what kills the e-tron’s efficiency in our opinion.

Article by Fred Lambert of elektrek

EPFL and MIT Researchers Discover the ‘Holy Grail’ of Nanowire Production

EPFL researchers have found a way to control and standardize the production of nanowires on silicon surfaces. Credit: Ecole Polytechnique Federale de Lausanne (EPFL)

Nanowires have the potential to revolutionize the technology around us. Measuring just 5-100 nanometers in diameter (a nanometer is a millionth of a millimeter), these tiny, needle-shaped crystalline structures can alter how electricity or light passes through them.

They can emit, concentrate and absorb light and could therefore be used to add optical functionalities to electronic chips. They could, for example, make it possible to generate lasers directly on silicon chips and to integrate single-photon emitters for coding purposes. They could even be applied in solar panels to improve how sunlight is converted into electrical energy.

Up until now, it was impossible to reproduce the process of growing nanowires on silicon semiconductors – there was no way to repeatedly produce homogeneous nanowires in specific positions.

But researchers from EPFL’s Laboratory of Semiconductor Materials, run by Anna Fontcuberta i Morral, together with colleagues from MIT and the IOFFE Institute, have come up with a way of growing nanowire networks in a highly controlled and fully reproducible manner. The key was to understand what happens at the onset of nanowire growth, which goes against currently accepted theories. Their work has been published in Nature Communications.

“We think that this discovery will make it possible to realistically integrate a series of nanowires on silicon substrates,” says Fontcuberta i Morral. “Up to now, these nanowires had to be grown individually, and the process couldn’t be reproduced.”

Two different configurations of the droplet within the opening – hole fully filled and partially filled and bellow illustration of GaAs crystals forming a full ring or a step underneath the large and small gallium droplets. Credit: Ecole Polytechnique Federale de Lausanne (EPFL)

 

Getting the right ratio

The standard process for producing nanowires is to make tiny holes in silicon monoxide and fill them with a nanodrop of liquid gallium. This substance then solidifies when it comes into contact with arsenic. But with this process, the substance tends to harden at the corners of the nanoholes, which means that the angle at which the nanowires will grow can’t be predicted. The search was on for a way to produce homogeneous nanowires and control their position.

Research aimed at controlling the production process has tended to focus on the diameter of the hole, but this approach has not paid off. Now EPFL researchers have shown that by altering the diameter-to-height ratio of the hole, they can perfectly control how the nanowires grow. At the right ratio, the substance will solidify in a ring around the edge of the hole, which prevents the nanowires from growing at a non-perpendicular angle. And the researchers’ process should work for all types of nanowires.

“It’s kind of like growing a plant. They need water and sunlight, but you have to get the quantities right,” says Fontcuberta i Morral.

This new production technique will be a boon for nanowire research, and further samples should soon be developed.

 Explore further: Nanowires have the power to revolutionize solar energy (w/ video)

More information: J. Vukajlovic-Plestina et al. Fundamental aspects to localize self-catalyzed III-V nanowires on silicon, Nature Communications (2019). DOI: 10.1038/s41467-019-08807-9

Journal reference: Nature Communications 

 

Johns Hopkins University ~ More flexible Nanomaterials can make Fuel Cell Cars Cheaper

A new method of increasing the reactivity of ultrathin nanosheets, just a few atoms thick, can someday make fuel cells for hydrogen cars cheaper, finds a new Johns Hopkins study.

A platinum-like metal only five atomic layers thick is “just right” for optimizing the performance of a fuel cell electrode. Credit: Johns Hopkins University image/Lei Wang

 

A report of the findings, to be published Feb. 22 in Science, offers promise towards faster, cheaper production of electrical power using fuel cells, but also of bulk chemicals and materials such as hydrogen.

“Every material experiences surface strain due to the breakdown of the material’s crystal symmetry at the atomic level. We discovered a way to make these crystals ultrathin, thereby decreasing the distance between atoms and increasing the material’s reactivity,” says Chao Wang, an assistant professor of chemical and biomolecular engineering at The Johns Hopkins University, and one of the study’s corresponding authors.

Strain is, in short, the deformation of any material. For example, when a piece of paper is bent, it is effectively disrupted at the smallest, atomic level; the intricate lattices that hold the paper together are forever changed.

In this study, Wang and colleagues manipulated the strain effect, or distance between atoms, causing the material to change dramatically. By making those lattices incredibly thin, roughly a million times thinner than a strand of human hair, the material becomes much easier to manipulate just like how one piece of paper is easier to bend than a thicker stack of paper.

“We’re essentially using force to tune the properties of thin metal sheets that make up electrocatalysts, which are part of the electrodes of fuel cells,” says Jeffrey Greeley, professor of chemical engineering at Purdue and another one of the paper’s corresponding authors. “The ultimate goal is to test this method on a variety of metals.”

“By tuning the materials‘ thinness, we were able to create more strain, which changes the material’s properties, including how molecules are held together. This means you have more freedom to accelerate the reaction you want on the material’s surface,” explains Wang.

One example of how optimizing reactions can be useful in application is increasing the activity of catalysts used for fuel cell cars. While fuel cells represent a promising technology toward emission-free electrical vehicles, the challenge lies in the expense associated with the precious metal catalysts such as platinum and palladium, limiting its viability to the vast majority of consumers. A more active catalyst for the fuel cells can reduce cost and clear the way for widespread adoption of green, renewable energy.

Chao Wang, a Johns Hopkins assistant professor of chemical and biomolecular engineering, in his lab with postdoctoral fellow Lei Wang, another author of the related research article. Credit: Will Kirk/Johns Hopkins University

Wang and colleagues estimate that their new method can increase catalyst activity by 10 to 20 times, using 90 percent less of precious metals than what is currently required to power a fuel cell.

“We hope that our findings can someday aid in the production of cheaper, more efficient fuel cells to make environmentally-friendly cars more accessible for everybody,” says Wang.

 Explore further: Gilding technique inspired by ancient Egyptians may spark better fuel cells for tomorrow’s electric cars

More information: L. Wang el al., “Tunable intrinsic strain in two-dimensional transition metal electrocatalysts,” Science (2019). science.sciencemag.org/cgi/doi … 1126/science.aat8051

Journal reference: Science  

Provided by: Johns Hopkins University  

 

Researchers at CUNY create guidelines for morphable nanomaterials to diagnose, target and effectively treat Life-Threatening Illness such as Cancer, Cardiovascular and Autoimmune diseases

Peptides spontaneously form spherical or worm-like nanostructures that can be morphed or broken down by enzymes overexpressed in cancer cells. By controlling the shape and charge of the nanostructures, scientists can predict the rate of …more

Scientists have long sought to develop drug therapies that can more precisely diagnose, target and effectively treat life-threatening illness such as cancer, cardiovascular and autoimmune diseases.

One promising approach is the design of morphable nanomaterials that can circulate through the body and provide diagnostic information or release precisely targeted drugs in response to disease-marker enzymes. Thanks to a newly published paper from researchers at the Advanced Science Research Center (ASRC) at The Graduate Center of The City University of New York, Brooklyn College, and Hunter College, scientists now have design guidance that could rapidly advance development of such nanomaterials.

In the paper, which appears online in the journal ACS Nano, researchers detail broadly applicable findings from their work to characterize a nanomaterial that can predictably, specifically and safely respond when it senses overexpression of the enzyme matrix metalloproteinase-9 (MMP-9). MMP-9 helps the body breakdown unneeded extracellular materials, but when levels are too high, it plays a role in the development of cancer and several other diseases.

“Right now, there are no clear rules on how to optimize the nanomaterials to be responsive to MMP-9 in predictable ways,” said Jiye Son, the study’s lead author and a Graduate Center Ph.D. student working in one of the ASRC Nanoscience Initiative labs. “Our work outlines an approach using short peptides to create enzyme-responsive nanostructures that can be customized to take on specific therapeutic actions, like only targeting tumor cells and turning on drug release in close proximity of these cells.”

Researchers designed a modular peptide that spontaneously assembles into nanostructures, and predictably and reliably morphs or breaks down into amino acids when they come in contact with the MMP-9 enzyme. The designed components include a charged segment of the nanostructure to facilitate its sensing and engagement with the enzyme; a cleavable segment of the structure so that it can lock onto the enzyme and determine how to respond; and a hydrophobic segment of the structure to facilitate self-assembly of the therapeutic response.

“This work is a critical step toward creating new smart-drug delivery vehicles and diagnostic methods with precisely tunable properties that could change the face of disease treatment and management,” said ASRC Nanoscience Initiative Director Rein Ulijn, whose lab is leading the work. “While we specifically focused on creating nanomaterials that could sense and respond to MMP-9, the components of our design guidance can facilitate development of nanomaterials that sense and respond to other cellular stimuli.”

Among other advances, the research team’s work builds on their previous findings, which showed that amino acid peptides can encapsulate and transform into fibrous drug depots upon interaction with MMP-9. The group is collaborating with scientists at Memorial Sloan Kettering and Brooklyn College to use their findings to create a novel cancer therapy.

 Explore further: Scientists create nanomaterials that reconfigure in response to biochemical signals

More information: Jiye Son et al, Customizing Morphology, Size, and Response Kinetics of Matrix Metalloproteinase-Responsive Nanostructures by Systematic Peptide Design, ACS Nano (2019). DOI: 10.1021/acsnano.8b07401

Journal reference: ACS Nano  

Provided by: CUNY Advanced Science Research Center

 

High Capacity Silicon Anodes Enabled by MXene Viscous Aqueous Ink ~ 2D MXene Nanosheets found to be of Fundamental Importance to Electrochemical Energy Storage Field ~ Trinity College, Dublin

** Contributed from Nature Communications Open Source Article

 

The ever-increasing demands for advanced lithium-ion batteries have greatly stimulated the quest for robust electrodes with a high areal capacity. Producing thick electrodes from a high-performance active material would maximize this parameter. However, above a critical thickness, solution-processed films typically encounter electrical/mechanical problems, limiting the achievable areal capacity and rate performance as a result.

Herein, we show that two-dimensional titanium carbide or carbonitride nano sheets, known as MXenes, can be used as a conductive binder for silicon electrodes produced by a simple and scalable slurry-casting technique without the need of any other additives.

“The nano sheets form a continuous metallic network, enable fast charge transport and provide good mechanical reinforcement for the thick electrode (up to 450μm). Consequently, very high areal capacity anodes (up to 23.3 mAh cm-2) have been demonstrated.” Utilization of Li-ion chemistry to store the energy electro-chemically can address the ever-increasing demands from both portable electronics and hybrid electrical vehicles.

 

Such stringent challenges on the battery safety and lifetime issues require high-performance battery components, with most of the focus being on electrodes or electrolytes with novel nano-structures and chemistries.

However, equally important is the development of electrode additives, which are required to main-tain the electrode’s conductive network and mechanical integrity. Traditionally, electrode additives are made of dual components based on a conductive agent (i.e. carbon black, CB) and a poly-meric binder.

 

While the former ensures the charge transport throughout the electrode, the latter mechanically holds the active materials and CB together during cycling. Although these traditional electrode additives have been widely applied in Li-ion battery technologies, they fail to perform well in high-capacity electrodes, especially those displaying large volume changes.

This is because the polymeric binder is not mechanically robust enough to withstand the stress induced during lithiation/deli-thiation, leading to severe disruption of the conducting networks. This results in rapid capacity fade and poor lifetime.

 

 

Continue Reading the Full Article from Nature Communications

 

 

 

 

Conclusion

In summary, the efficient utilization of 2D MXene nanosheets as a new class of conductive binder for high volume-change Si electrodes is of fundamental importance to the electrochemical energy storage field.

The continuous network of MXene nanosheets not only provides sufficient electrical conductivity and free space for accommodating the volume change issue but also well resolves the mechanical instability of Si. Therefore, the combination of viscous MXene ink and high-capacity Si demonstrated here offers a powerful technique to construct advanced nanostructures with exceptional performance.

Of equal importance is that the formation of these high-mass-loading Si/MXene electrodes can be achieved by means of a commercially compatible, slurry-casting technique, which is highly scalable and low cost, allowing for large-area production of high-performance, Si-based electrodes for advanced batteries.

Considering that more than 30 MXenes are already reported, with more predicted to exist, there is certainly much room for further improving the electrochemical performance of such electrodes by tuning the electrical, mechanical and physicochemical properties of this exciting 2D MXene family.

Professor Valeria Nicolosi 

Professor of Nanomaterials and Advanced Microscopy at Trinity College Dublin

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